Key takeaways:
Rhabdomyolysis occurs when muscles break down and leak toxic byproducts into the bloodstream. These byproducts can then clog up the kidney and lead to kidney dysfunction.
There are many causes of rhabdomyolysis. Examples include medications and drugs, traumatic muscle injury, and infections.
The most common symptoms of rhabdomyolysis are muscle pain, weakness, and dark-colored urine.
You may recognize the term “rhabdomyolysis” as a potential side effect of some common medications, like statins — the most common cholesterol medications. It has also gained some attention as a serious complication of intense exercise routines.
Rhabdomyolysis is a medical condition that occurs when muscle tissue breaks down and leaks into the bloodstream. It can happen with direct injury to the muscle — like with crush injury or heavy weight lifting. But it can also be a side effect of medication or other medical conditions — like diabetes or certain infections. So we’ll explain more about who is at risk for this condition, common symptoms, and treatment.
Rhabdomyolysis can occur when muscle tissue breaks down. It starts with an increase in calcium in the muscle cell. When this happens, muscle components — like creatine kinase, myoglobin, and electrolytes — are released into the bloodstream. And this can become a problem when these byproducts reach a level that is toxic to the body.
The kidney is one of the main affected organs. Myoglobin can be harmful to the kidneys, and it can clog up their filtration system as the kidneys try to remove the myoglobin from the body. When this happens, rhabdomyolysis can cause rapid and serious kidney failure. And, in rare cases, it can lead to death.
It makes sense that any significant injury to a muscle can lead to rhabdomyolysis. But many different conditions and medications can cause rhabdomyolysis, too. Causes of rhabdomyolysis include:
Trauma: Rhabdomyolysis is more likely with significant crush-type injuries, like when part of the body is trapped under or between heavy objects.
Overexertion: This can occur in extreme forms of exercise, like when someone performs heavy weight lifting, especially if they aren’t physically trained for it. Exercise in extreme heat can also cause overexertion.
Ischemia: This refers to a lack of blood flow. If muscles do not have good blood flow, then the muscle starts to die and break down. This can happen in conditions like blood clots, immobilization (lying in a hospital bed for weeks), or severe swelling in a muscle (compartment syndrome).
Drugs and medications: A range of medications and drugs can lead to rhabdomyolysis (more on this below).
Toxins: Examples include carbon monoxide, snake venom, and mushroom ingestion.
Infections: Several bacterial and viral infections have been associated with rhabdomyolysis. Some examples include the influenza virus, Staphylococcus aureus, and the Epstein-Barr virus (a cause of mono).
Metabolic disorders: Examples of this include excessively high blood sugar levels (that can happen in diabetic ketoacidosis), electrolyte abnormalities (such as very low levels of potassium or phosphate), and inherited genetic conditions of metabolism.
Extremes of body temperature: Examples include hypothermia, heat stroke, and malignant hyperthermia (a reaction to anesthesia).
Overexcited states: These are situations where the muscles are more contracted than normal. Examples include seizures, delirium tremens (which can occur with alcohol withdrawal), psychotic agitation, and amphetamine overdose.
A variety of medications have been linked to rhabdomyolysis. Like all other causes of rhabdomyolysis, these medications increase the amount of calcium inside a muscle cell, which kicks off a cascade that leads to muscle breakdown. The most commonly associated medications and drugs include:
Statins
Antipsychotics medications
HIV medications, like Zidovudine (Retrovir)
Gout medications, like colchicine
SSRI antidepressants, like Zoloft (sertraline) or paroxetine (Paxil)
Anesthesia medicines
Cocaine, heroin, and other recreational substances
About half of the time, rhabdomyolysis occurs within 1 month of starting a new medication.
The three most common signs and symptoms of rhabdomyolysis include:
Muscle pain: This usually feels more severe than mild or expected soreness.
Weakness: Similar to pain, this is usually more noticeable than normal fatigue or lack of energy. It may feel like you can’t complete simple tasks — like standing up from a chair or carrying a bag of groceries.
Tea- or cola-colored urine: Myoglobin in the urine has a brownish-red appearance, similar to blood.
Other symptoms that can occur with rhabdomyolysis include:
Stomach pain
Nausea
Vomiting
Fever
Limb swelling
Rapid heart rate
Confusion
Dehydration
Reduced or no urine output
Muscle stiffness and cramping
The goal of rhabdomyolysis treatment is to prevent kidney injury. This is mainly done by keeping someone well hydrated with IV (intravenous) fluids that help flush out the kidneys. It also requires careful electrolyte replacement, with doses of IV potassium and calcium.
For most people, this treatment occurs over several days in the hospital under close monitoring. If your kidney function is not improving, in some cases you may need dialysis. This is often just for a short period of time — to give your kidneys time to recover. Most people with kidney injury from rhabdomyolysis fully recover their kidney function.
Rhabdomyolysis is a serious medical condition. It requires treatment in a hospital with IV fluids and medication to prevent kidney failure and serious complications. So it’s best not to try and ride it out at home or hope it will resolve itself. If you think you may be experiencing some of the symptoms mentioned above, see your provider as soon as possible.
Many things can lead to muscle aches or pains, so it’s important to let your provider know about any side effects you experience. Be sure to have this conversation before stopping or making any changes to your prescription medications.
Keep in mind that rhabdomyolysis is not a subtle ache or pain, and it’s a rare reaction. Your provider may have you stop your medication for 2 weeks to see if the symptoms resolve. Or they may perform a blood test that can confirm a diagnosis of rhabdomyolysis.
Rhabdomyolysis is a serious medical condition. It can occur after a serious accident or as a side effect of some commonly prescribed medications. Common symptoms include muscle pain, weakness, and dark urine. Talk to your healthcare provider if you notice new symptoms of muscle pain, especially after changes in your medication regimen.
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